1. Field of the Invention
The present invention relates to an image sensor module.
2. Description of the Related Art
Image sensor modules are widely used to read the content in an object to be read, in the form of image data. The image sensor module is, for example, incorporated in a document scanner, to read the content of an object to be read relatively moving in a sub scanning direction, as image data. For example, JP-A-2007-300536 discloses an image sensor module configured to emit linear light extending in a main scanning direction to an object to be read, and to receive the reflected light with a sensor IC.
The image sensor according to JP-A-2007-300536 includes a light emitting unit, a photodetector, a lens unit, a substrate, and a case. The light emitting unit, which emits linear light, has an elongate shape in the main scanning direction. The photodetector extends in the main scanning direction and is mounted on the substrate. The lens unit also extends in the main scanning direction, and serves to converge the linear light reflected by the object to be read on the photodetector. The case accommodates therein the light emitting unit, the lens unit, the photodetector, and the substrate, and has a block shape extending in the main scanning direction. The case is formed of, for example, a resin material. Since the case is elongate in the main scanning direction, an error in size (distortion) from the design may be incurred at a position in the main scanning direction. When the case includes a distorted portion, the positional relationship between the lens unit and the photodetector enclosed in the case deviates from the designed value, which may lead to deviation of the focal point of the lens unit.